- L.J. Phillips-Wood, Dolson Co., Inc.27
- L.V. Hoffman and Co.4
- Lafayette Gardens Terrace, Inc.1
- Laiffer, Peggy1
- Land Properties Inc.1
- Landau, Samuel J.2
- Landau-Banker Realty Corp.2
- Lansco Corp.2
- Lark Equities1
- Lasette, Frank B.3
- Lautob Realty1
- Lawrence M. Rosenthal Associates1
- Lazarus, Frank L.3
- Leacrest Corp.1
- Leo Silver Sons, Inc.1
- Leon Finley, Harry Seeve and Associates3
- Leonard J. Beck, Inc.3
- Leonard P. Hall Co.1
- Lester, Eugene R.3
- Levy, Edgar A.1
- Lewis, Alfred2
- Lex-56th Corp.5
- Lexanne Realty Corp.2
- Lexington Estates, Inc.1
- Lexington Holding Corp.1
- Lexington House, Inc.2
- Liebman, Harold M.1
- Limebud Realty Corp.1
- Lipman Associates Inc.2
- Lofts for Living Ltd.2
- London 68 Co.5
- London Management Corp.2
- Louis Carreau, Inc.1
- Lyras, Steven C.2
- Lyras-Adams Limited2
- M. and L. Hess Inc.1
- MUHS Servicing, Inc.2
- MacArthur Construction Co.6
- Mack and Davis, Inc.3
- Macklowe, Harry2
- Madison Square Garden Center, Inc.1
- Manhattan Luxury Loft Co.1
- Manoochehrian Bros.8
- Marben Building Corp.2
- Marble Hill Gardens, Inc1
- Marcus Brown Construction Co., Inc.2
- Marcus Brown and Sons1
- Mark Rafalsky & Co.2
- Mark Rafalsky and Co., Inc.11
- Martin Construction Corp.1
- Martin, John S.3
- Marx Realty and Improvement Co., Inc.2
- Marx, Julian L.1
- Marx, Ludwig2
- Massachusetts Mutual Life Insurance Co.3
- Match, Harry1
- Match, Jack1
- Matmar Realty Corp.1
- Mayers, J. Lewis1
- Mayfair House Corp.1